Sub-$20K Supercar: 1990 Chevrolet Corvette ZR-1 (opens in new tab)

Sometimes, there is a tell-tale sign that a car is simply not going to over-perform in the coming years as it relates to value. The C4 chassis Chevrolet Corvette has long been a bargain, but sadly, far too many were made for it to ever be considered particularly rare or hard to come by. The...